Multifocal visual evoked potential evaluation for diagnosis of acute optic neuritis and for prediction of visual outcome and ganglion cell layer thinning following optic neuritis

BACKGROUND

While damage to the optic nerve following optic neuritis (ON) is readily quantifiable, the evaluation of prognosis for visual function and neuroaxonal loss in the acute ON is challenging.

OBJECTIVE

The objective of this study is to investigate the value of multifocal visual evoked potential (mfVEP) in acute ON, diagnostically for acute ON and prognostically for visual outcome and subsequent ganglion cell/inner plexiform layer thickness (GCLIPLt).

METHODS

A prospective cohort study of mfVEP and full-field visual evoked potential (ffVEP) in acute, unilateral ON (onset < 31 days) was conducted. Comparisons with healthy controls (n = 30) and association analysis with follow-up optical coherence tomography (OCT) measurements (of the GCLIPLt) and visual function (Sloan low-contrast visual acuity (LCVA)) were conducted.

RESULTS

Seventy-nine ON patients were included (mean: 17 days from onset). Excluding measurements with conduction block, ffVEP (n = 54) and mfVEP (n = 44) showed sensitivities of 89% and 84% to a specificity of 97%. 65/79 patients were re-examined (mean: 200 days follow-up). mfVEP amplitude and latency inter-eye asymmetry in acute ON correlated with GCLIPLt (r = 0.587 and Spearman's ρ = 0.597, for both, p < 0.001). mfVEP amplitude correlated with LCVA inter-eye asymmetry at follow-up (r = 0.421, p < 0.001), mfVEP latency did not.

CONCLUSION

mfVEP may support the prognostic evaluation of acute ON patients and prove valuable in future neuroprotective and remyelinating trials. In acute ON, the increase in diagnostic value of mfVEP to ffVEP may be limited due to widespread conduction block.

Multifocal Visual Evoked Potentials (mfVEP) for the Detection of Visual Field Defects in Glaucoma: Systematic Review and Meta-Analysis

Some discrepancies have been observed in the diagnostic efficacy of multifocal visual evoked potential (mfVEP) when evaluating visual field defects in glaucoma patients. Therefore, we evaluated the diagnostic precision of the mfVEP in glaucoma to find its best diagnostic indicator. A systematic review and meta-analysis of quantitative studies published up to 1 April 2021 was performed. The methodological quality of the included articles was assessed. Publication bias analysis and heterogeneity tests were performed. The sensitivity, specificity and diagnostic odds ratio were calculated. The area under the curve (AUC) was calculated using the summary of receiver operating characteristics curve. Six studies with a total of 241 patients were included according to the inclusion and exclusion criteria. The AUC was 0.98. There was no evidence of publication bias or threshold effect. The pooled sensitivity and pooled specificity of the mfVEP amplitude for detection of visual field defects in all studies was 0.93 and 0.89, respectively. The positive and negative likelihood ratios of mfVEP amplitude were 6.56 and 0.08, respectively. The amplitude of mfVEP showed a good diagnostic precision in the prediction of visual field defects. Interocular mfVEP amplitude analysis can be a good diagnostic indicator for visual field study.

Treating amblyopia in adults with prosthetic occluding contact lenses

PURPOSE

To investigate the feasibility, effectiveness and acceptability of using prosthetic occluding contact lenses (OCLs) to treat moderate amblyopia in adults and of the role of the multifocal visual evoked potential (mfVEP) as a predictor of postamblyopic therapy.

METHODS

A comparative, prospective, interventional, case series pilot study with amblyopic adults (mean age: 40 years, range 20-50 years) allocated into two intervention groups: eye patching and OCL. The primary outcome variable was logarithm of the minimum angle of resolution (logMAR) best-corrected visual acuity (BCVA), and secondary outcomes were mfVEP amplitude and latency and patients' health-related quality of life National Eye Institute Visual Function Questionnaire (NEI VFQ-25).

RESULTS

Significant improvements in pre- to postamblyopic therapy BCVA were seen at 1.5 months in the OCL group [0.29 logMAR, 95% confidence interval (CI): 0.10-0.47 versus 0.11 logMAR, 95% CI: 0.02-0.19; p < 0.001] and eye patching group (0.29 logMAR, 95% CI: 0.17-0.40 versus 0.18 logMAR, 95% CI: 0.12-0.23; p < 0.01). Post-treatment BCVA was inversely related to age (R: 0.009, 95% CI: -0.02 to -0.001; p = 0.04) and the presence of strabismus (R: -0.3, 95% CI: -0.434 to -0.17; p = 0.001). No significant changes in the number and size of the abnormal mfVEP amplitude and latency defects were observed after occlusion. The NEI VFQ-25 composite score showed significant improvement in the OCL users at 12 months compared to eye patching.

CONCLUSION

Significant vision improvement can be achieved, making occlusion with OCLs an effective and more acceptable therapy for adults with amblyopia.

Multifocal visual evoked potentials for quantifying optic nerve dysfunction in patients with optic disc drusen

PURPOSE

To explore the applicability of multifocal visual evoked potentials (mfVEPs) for research and clinical diagnosis in patients with optic disc drusen (ODD). This is the first assessment of mfVEP amplitude in patients with ODD.

METHODS

MfVEP amplitude and latency from 33 patients with ODD and 22 control subjects were examined. Mean amplitude, mean inner ring (IR) amplitude (0.87-5.67° of visual field) and mean outer ring amplitude (5.68-24° of visual field) were calculated using signal-to-noise ratio (SNR) and peak-to-peak analysis. Monocular latency was calculated using second peak analysis, while latency asymmetry was calculated using cross-correlation analysis.

RESULTS

Compared to normals, significantly decreased mean overall amplitude (p < 0.001), IR amplitude (p < 0.001) and outer ring amplitude (p < 0.001) were found in ODD patients when using SNR. An overall monocular latency delay of 7 ms was seen in ODD patients (p = 0.001). A significant correlation between amplitude and automated perimetric mean deviation as well as retinal nerve fibre layer thickness was found (respectively, p < 0.001 and p = 0.003). The overall highest correlation was found in this order: outer ring, full eye and IR. In the control group, SNR intersubject variability was 17.6% and second peak latency intersubject variability was 2.8%.

CONCLUSION

Decreased mfVEP amplitude in patients with ODD suggests a direct mechanical compression of the optic nerve axons. Our results suggest that mfVEP amplitude is applicable for the assessment of optic nerve dysfunction in patients with ODD.

Multifocal visual evoked potentials in amblyopia due to anisometropia

PURPOSE

To investigate multifocal visual evoked potentials (mfVEP) of the amblyopic and fellow eye in amblyopia due to anisometropia.

METHODS

We recorded mfVEP in both eyes of 15 anisometropic amblyopic patients and 15 normal control subjects. The responses from the central 7.0 degrees arc of the visual field were measured, and changes in latency and amplitude were compared between the amblyopic, fellow, and normal control eyes.

RESULTS

There was a significant difference in the latency and amplitude of mfVEP between the amblyopic and fellow eyes. The responses in the central region of the visual field (rings 1 and 2) had a longer latency and smaller amplitude in the amblyopic eye. In contrast, there was no difference in mfVEP latency or amplitude between the fellow eye and normal control eyes.

CONCLUSION

These results suggest that mfVEP may be used as an alternative objective method for diagnosis and monitoring of anisometropic amblyopia.